GENERAL INFORMATION
The abductor digiti minimi is a muscle located in the foot that plays a vital role in stabilising the foot, supporting the arches and controlling the movement of the fifth toe. It is part of the first layer of muscles in the foot.
ORIGIN
The abductor digiti minimi muscle originates from specific points within the foot. The origins of the abductor digiti minimi are as follows:
- Medial and lateral processes of the calcaneal tuberosity (heel bone)
INSERTION POINT
The abductor digiti minimi muscle inserts at the following point:
- The lateral side of the proximal phalanx of the fifth toe
MAJOR ARTERIES
The abductor digiti minimi muscle receives its blood supply from various arteries, including:
- Plantar arteries: These arteries branch from the posterior tibial artery as well as provide blood supply to the plantar aspect of the foot, including the abductor digiti minimi muscle.
NEURAL INNERVATION
The abductor digiti minimi muscle is innervated by the lateral plantar nerve, a tibial nerve branch.
TRIGGER POINT
Trigger points, as well as localised areas of muscle tension and sensitivity, can develop in the abductor digiti minimi muscle due to various factors such as overuse, muscle imbalances, as well as trauma. These trigger points can cause foot pain and discomfort, also called abductor digiti minimi trigger point pain.
CONCENTRIC FUNCTION
The abductor digiti minimi muscle functions concentrically when it contracts to actively move the fifth toe away from the midline of the foot, also a movement known as toe abduction.
ECCENTRIC FUNCTION
The abductor digiti minimi muscle also functions eccentrically to control the movement as well as decelerate forces acting on the foot during toe adduction, which is the movement of bringing the fifth toe back toward the midline of the foot.
ISOMETRIC FUNCTION
Isometric contractions of the abductor digiti minimi muscle occur when the muscle generates force without changing its length. These contractions help provide stability to the foot during weight-bearing activities.
RELATED MUSCLE SCIENTIFIC NAMES
- Abductor digiti minimi: Musculus abductor digiti minimi
ANTAGONIST
The antagonist muscle to the abductor digiti minimi is:
- Adductor hallucis: The adductor hallucis muscle acts as an antagonist to the abductor digiti minimi muscle. It brings the fifth toe back toward the foot’s midline during toe adduction.
COMMON INJURIES
Common injuries as well as conditions associated with the abductor digiti minimi muscle include:
- Strains or sprains: Overstretching or tearing of the abductor digiti minimi muscle due to excessive force or trauma.
- Tendinitis: Inflammation of the tendon of the abductor digiti minimi muscle, often caused by overuse as well as repetitive strain.
EXERCISES
Exercises that target the abductor digiti minimi muscle include:
- Toe abduction exercises: Sit on a chair and place a resistance band around your fifth toe. Slowly move your fifth toe away from the foot’s midline against the band’s resistance, focusing on activating the abductor digiti minimi muscle.
- Toe towel scrunches: Place a towel on the floor, use your fifth toe to scrunch and pull the towel toward you, emphasising the activation of the abductor digiti minimi muscle.
- Single-leg balance: Stand on one leg and focus on maintaining balance while engaging the abductor digiti minimi muscle to stabilise the foot and control toe abduction.
STRETCHES
Stretches that can help stretch the abductor digiti minimi muscle include:
- Toe abduction stretch: Sit on a chair and cross one leg over the opposite thigh. Pull your fifth toe away from the foot’s midline, stretching the abductor digiti minimi muscle.
- Plantar fascia stretch: Sit on a chair and place the affected foot over the opposite thigh. Pull your toes back using your hand, stretching the plantar fascia and indirectly stretching the abductor digiti minimi muscle.
